Kilmat Sound Deadening Failure

In the submitted examples shown, Kilmat appears to display two different but related failure behaviors.

In one submitted roof example, the material appears to have released from the roof and left behind a nasty, greasy, vaseline-like butyl residue along with visible staining. This does not look like poor prep or simple user error. It also does not need to be framed as a classic heat-melt event. It looks more like a low-quality, unstable butyl formula that left behind a contaminating residue and lost the ability to remain properly adhered.

I have personally seen very similar behavior from similar products in the past, Noico being one example. Kilmat and Noico were long thought to be made in the same factory, though I am not stating that here as a confirmed fact.

In a separate submitted removal example, the issue looks different, but just as telling. As the material is peeled back after being installed for a while, the butyl easily stretches, strings out, shows small air pockets, and does not want to recover or snap back into its original place or shape. That is not what you want to see from a viscoelastic damping layer. More importantly, that kind of behavior shows signs that the butyl may have been bulked up with useless “volume fluffer” additives, such as foaming agents and similar low-cost fillers, used to increase volume and reduce cost at the expense of actual viscoelastic performance. In other words, it looks like a formula built to create more material for less money, not one built to perform well as a proper constrained layer damper.

Based on the visible behavior in these submitted examples, combined with the general poor performance shown in testing of the product, the most likely cause is a very poor butyl formula loaded with additives that do little or nothing to help the material perform as a proper constrained layer damper. In the case of the stretching, stringing, and air-pocket behavior, it points toward a formula that may have been artificially bulked up with cheap volume-increasing additives rather than engineered for strong, stable viscoelastic damping behavior.

Something else to note, the visible mess was almost certainly not the beginning of the failure. In both submitted examples, functional failure was definitely happening before the visible failure became obvious. A CLD that has lost elasticity to this degree, or one that leaves behind a nasty contaminating residue and falls off, was not still meaningfully controlling panel resonance right up until the moment it became easy to see.

Kilmat has a long enough history of complaints that these submitted examples are not surprising. The problem is that so many people use it because of the low price that inexperienced users who are happy with the cheap cost often drown out the complaints. That does not change what is shown here.